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Hi guys,So now my Z4 is all good I thought I’d take this opportunity to give the e36 some love,chucking in a new clutch also I had a slight oil weep on my lower timing chain cover,so I thought I’d fix this while the cars off the road then removed oil filter housing to change this gasket also,I’d say the engine internally isn’t sludgy at all but I wouldn’t say it’s clean either having done 104 k miles,and I’d like to give it a real good clean where I can.
So my question is this,Can I use an engine degreaser and pour some through the oil filer hole in the block?,surely everything will end up in the sump anyway where I can drain it out.

If you really want to clean the engine internals then an engine flush could be used. I wouldn’t use anything not designed for the purpose.

I wouldn’t do that, the degreaser could remove the film of oil between the cam & its bearings, get in the oil pump and other unwanted places.
I’d use an engine flush before draining the oil & leave it at that.
Rob

Aren’t engine flush products meant to be used with the engine running?im not needing to do that at the moment I’m looking for a product i can use before I put it all back together,I’m not really wanting to remove the sump at the moment but probably will

Robster68 wrote: ↑Sat May 14, 2022 11:06 pm Aren’t engine flush products meant to be used with the engine running?im not needing to do that at the moment I’m looking for a product i can use before I put it all back together,I’m not really wanting to remove the sump at the moment but probably will

Yes, engine flush is used with the engine running. Unless you’re planning a complete strip down & rebuild you shouldn’t use a degreaser on your engines internal parts, you could cause some bad damage.
Rob

I’ve seen a few videos online where flushing with diesel /kerosene is mentioned,I’m not familiar with the internal oil ways etc but if I pour in something through oil filter hole surely it exits into the sump area taking old oil with it or maybe I could use some clean cheap thin engine oil

If there’s no heavy buildup or problems then personally I wouldn’t bother. A bit of varnish on the cams/rocker cover is no issue and neither is a bit of carbon on the pistons. You’d be better off cleaning out the breathing and idle related pipe work/valves and making sure you don’t have any splits in the intake pipes etc.

At most I’d run some specific engine cleaner through it and drop the oil after. You could always put some injector cleaner through a couple of tanks of fuel for good measure but I’m not sure how effective these really are.

I’ve seen a couple of videos where a tank of water has been connected to the intake side and fed in to the combustion chambers very gradually to ‘steam clean’ the pistons. I think there are pretty mixed opinions and results with this though.

TL:DR If it ain’t broke, don’t fix it, and don’t pour something in to the engine that will strip internal parts of their oil film!

Thanks for the detailed replies guys,yes I’m replacing what I can without going stupid,although I’m enjoying the process and am not in a rush